| Shijiazhuang is located in the Beijing Tianjin and Hebei region of which the energyconsumption is rising and the regional air pollution becomes more and more serious dayby day. The particles with different diamter have become the primary pollutant in theatmosphere. Up to now there is no study on the PAHs in the different diameter particles ofShijiazhuang. This paper established suitable analysis method for the determination ofPAHs in Shijiazhuang, got a large number of analysis data and provided scientific supportfor the finding of the variation regularity of the pollutant components and changecharacteristics, the environmental impact assessment, and the establishment of reasonableair pollutants control measures.The samples were collected in the6state automatic monitoring stations inShijiazhuang during heating and non-heating seasons. The mass concentrations of TSP,PM10and PM2.5were analyzed. The16kinds of optimal polycyclic aromatic hydrocarbonswere analyzed innovatively in TSP, PM10and PM2.5and summed up the changecharacteristics before and after heating period in Shijiazhuang.1) Manually collected PM2.5, PM10and TSP samples within a long period whichcontained all the four seasons for the first time and got369samples and6273data. Gotthe first hand data of PAHs in the airborne particulate matter in Shijiazhuang.2) According to the characteristics of PAHs pollution in Shijiazhuang, suitabledetermination method was established. The pretreatment method, the purification method,and the chromatographic conditions were all improved. The recovery rate was between69.4%and106%, the correlation coefficient was between0.9994and0.9999,and theprecision and accuracy were satisfactory. The pretreatment methods reduced the use oftoxic organic solvents, improved the recovery rates of PAHs; the mobile phase used in theLC was with low toxicity, the recoveries and correlation coefficient for the low ring PAHswere also very well. This determination method was suitable for large range ofconcentration and could be used for fast and accurate analysis of large amount of samples.3) The research combined with industrial layout and main air pollution source ofShijiazhuang, analyzed change characteristics of PAHs in the airborne particle matterbefore and after heating period and the spatial distribution characteristics of PAHs.(1) The mass concentration of TSP, PM10and PM2.5were all in high level in winter and spring, but the mass concentration of the airborne particulate matter with differentdiameters changed intensively in winter because of the influence of meteorologicalconditions, moreover, the spring changed slowly.(2) The air polluting characteristic of Shijiazhuang belonged to the typical northerncity of China. PAHs concentration was significantly higher in heating period than nonheating period.15kinds of PAHs were detected in winter and14in spring. Theconcentration of BaP in PM10in winter was17.058ng/m3and the total concentration ofPAHs was290.159ng/m3; the concentration of BaP in PM2.5was15.702ng/m3and thetotal concentration of PAHs was253.695ng/m3. The concentration of BaP in PM10inspring was5.733ng/m3and the total concentration of PAHs was75.757ng/m3; Theconcentration of BaP in PM2.5was5.157ng/m3and the total concentration of PAHs was63.482ng/m3. It was found that there was significant correlation between BaP and PAHsand the regression equation was established in two seasons.(3) The space distribution during heating and non-heating period of PAHs was verydifferent in Shijiazhuang. The pollution in in the suburbs was serious than the city centerin winter, but inverse in spring. It had relation with the surrounding industry, traffic andlive condition.4) This study analyzed the ratio between PAHs with different ring. It showed that themain source of PAHs was the local source in heating and non-heating period. The mainsource was identified by characteristic ratio method. It showed that the componentvariation of PAHs during heating and non-heating period was mainly because of thechange of fuel ratio and the seasonal change of the pollution source. The BaP/BghiP ratiowas between0.952and1.348in winter in PM10which belong to coal combustioncharacteristic, so that the PAHs in PM10in the winter of Shijiazhuang was mainly affectedby the coal burning; The BaP/BghiP ratio was between0.673and0.929in spring in PM10which belong to mixed source characteristic, so that the PAHs in PM10in spring ofShijiazhuang was mainly affected by coal buring and traffic sources.The characteristicration result of PM2.5was similar to that of PM10. |
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